研究了城市生污泥和熟污泥对Cd的吸附解吸特性及其差异性。结果表明:生污泥和熟污泥对Cd2+的吸附量均随着平衡溶液中Cd2+离子浓度的增加而增加,但增加速率渐趋缓慢,生污泥对Cd2+的吸附量小于熟污泥,Freundlich型吸附等温线方程是描述生污泥或熟污泥对Cd2+的吸附量和Cd2+平衡浓度之间关系的最佳模型。生污泥和熟污泥的解吸率均随着Cd2+初始浓度的升高而持续增大,但增加速率整体上在下降,生污泥的解吸率略高于熟污泥。生污泥和熟污泥对Cd2+的解吸量均随着污泥中Cd2+吸附量的增加而增加,且二者呈显著正相关关系(P〈0.001)。
This research investigated the adsorption and desorption of cadmium in sewage raw sludge and composted sludge and their differences. The adsorption of cadmium in the sewage raw sludge and composted sludge slowly increased with the equilibrium concentration increased,and the curve flattened. The adsorption of cadmium in the sewage raw sludge was less than that in composted sludge. Cadmium adsorption behavior could be well described by Freundlich equation. With the equilibrium concentration increased,desorption rate of cadmium increased,but the increase rate decreased from the global aspect. The desorption rate in sewage raw sludge was higher than that in composted sludge. The desorption of cadmium in sewage raw sludge and composted sludge increased with the adsorption of cadmium in sludge increased,and there was significant positive correlation between adsorption and desorption of cadmium in sludge( P 0. 001).